Network layer< - CompWisdom

Network layer< - CompWisdom

Meaningful results bit by bit

About us | Why use us? | Press | Contact us

Topic: Network layer<

Ads by Google



OSI model - Wikipedia, the free encyclopedia

The Networkb> layer provides the functional and procedural means of transferring variable length data sequences from a source to a destination via one or more networks while maintaining the quality of service requested by the Transport layer.
The Data Link layer provides the functional and procedural means to transfer data between networkb> entities and to detect and possibly correct errors that may occur in the Physical layer.
Usually, the implementation of a protocol is layered in a similar way to the protocol design, with the possible exception of a 'fast path' where the most common transaction allowed by the system may be implemented as a single component encompassing aspects of several layers.

http://en.wikipedia.org/wiki/OSI_model (1492 words)



Networkb> Protocol Levels

When starting with protocols that work at the upper layers of the networkb> models, each set of data is wrapped inside the next lower layer protocol, similar to wrapping letters inside an envelope.
Networkb> - Corresponds to the networkb> layer of the OSI model and includes the IP, ICMP, and IGMP protocols.
Assuming there is a direct connection between the two computers, the networkb> interface card on machine B, will recognize its MAC address and grab the data.

http://www.comptechdoc.org/independent/networking/guide/netstandards.html (1781 words)



RFC 941 - Addendum to the networkb> service definition covering networkb> layer addressing. International Organization for Standardization.

A Networkb> Layer protocol which is capable of conveying a string of variable length with a maximum length of either 20 binary octets or 40 decimal digits is capable of encoding the full semantic content of any Networkb> Address.
RFC 941 April 1985 Networkb> Layer Addressing protocol specifications making reference to this Addendum shall specify the way in which either the decimal concrete syntax or the binary concrete syntax of the NSAP address (or both) is encoded as NPAI (see clause 6.1.3).
RFC 941 April 1985 Networkb> Layer Addressing 8.2.1.2 Format and Allocation of the IDI A specific combination of IDI format and DSP abstract syntax is associated with each allocated AFI value, as summarized in Table 8-2: Table 8-2: AFI Values ___________________

http://rfc.sunsite.dk/rfc/rfc941.html (5841 words)



Mobility Management is a Networkb> Layer Function

Conventional data networkb> routing table updates must be done frequently enough to prevent congestion in the event of a link or router failure or networkb> reconfiguration.
The assignments of networkb> layer addresses to hosts is based on the topology (state of connectivity) of the networkb>.
By definition, routing is a networkb> layer function and thus mobility management should also be a networkb> layer function.

http://www.leapforum.org/published/internetworkMobility/split/node22.html (1006 words)



O'Reilly Networkb> -- The Scholar's Approach to the Internet

This layer may encompass the operating system on your computer, the networkb> interface card, and its device driver.
The lower layers of the OSI model are responsible for the physical connectivity of the host and the routing of data in the networkb>.
The bottom sections of the model -- networkb>, datalink, and physical -- are sometimes referred to as the networkb> layer, and provide delivery of data up to the transport layer, which in turn relays the information to the application layer.

http://www.oreillynet.com/pub/a/network/2001/02/09/net_2nd_lang.html (1404 words)



RFC 2956 (rfc2956) - Overview of 1999 IAB Networkb> Layer Workshop

The goal of the workshop was to understand the state of the networkb> layer and its impact on continued growth and usage of the Internet.
There are multiple causes for the loss of transparency, for example the deployment of networkb> address translation devices, the use of private addresses, firewalls and application level gateways, proxies and caches.
The goal of the workshop was to discuss the current state of the Networkb> Layer and the impact various currently deployed or future mechanisms and technologies might have on the continued growth and usage of the Internet.

http://www.faqs.org/rfcs/rfc2956.html (4114 words)



Networkb> Layer: Introduction and Service Models

The networkb> layer will then typically inform the end system on the other side of the networkb> of the call termination, and update the data structures in the packet switches on the source-to-destination path to indicate that the connection no longer exists.
In an analogous manner, some networkb> layer architectures (e.g., ATM) requires that the routers along the chosen path from source to destination handshake with each other in order to setup state before data actually begins to flow.
The role of the networkb> layer in a sending host is to begin the packet on its journey to the the receiving host.

http://gaia.cs.umass.edu/kurose/network/service/service.htm (2729 words)



Networkb> protocols: Networkb> Layer

A host is essentially anything on the networkb> that is capable of receiving and transmitting IP packets on the networkb>, such as a workstation, server or a router.
The high-level IP-based networking software in a given station is aware of its own 32-bit IP address and can read the 48-bit Ethernet address of its networkb> interface, but it doesn't know what the Ethernet addresses of other stations on the networkb> may be.
Through the use of SNMP networkb> devices such as routers can be configured by any host on the LAN.

http://www.geocities.com/dinbbil30/cor6.html (3986 words)



rfc1208.txt

To do this it uses a routing protocol to gain information about the networkb>, and algorithms to choose the best route based on several criteria known as "routing metrics." In OSI terminology, a router is a Networkb> Layer intermediate system.
Networkb> Layer: The OSI layer that is responsible for routing, switching, and subnetwork access across the entire OSI environment.
Data Link Layer: The OSI layer that is responsible for data transfer across a single physical connection, or series of bridged connections, between two Networkb> entities.

http://www.ietf.org/rfc/rfc1208.txt (4549 words)



O'Reilly Networkb> -- Layer 3 Switching -- Introducing the Router

Diagram of a simple two-segment networkb> with a layer 3 router.
Her background will be instrumental in helping them decide if they can continue to grow with a layer 2 switching architecture, of if they need to add routers to their topology.
The primary function of the router is to determine the best networkb> path in a complex networkb>.

http://www.oreillynet.com/pub/a/network/2001/04/13/net_2nd_lang.html (629 words)



ISO/OSI Networkb> Model

This layer defines the networkb> hardware and device drivers.
The networkb> layer may have to break large datagrams, larger than MTU, into smaller packets and host receiving the packet will have to reassemble the fragmented datagram.
The leading 1-3 bytes of the IP identify the networkb> and the remaining bytes identifies the host on that networkb>.

http://www.uwsg.indiana.edu/usail/network/nfs/network_layers.html (754 words)



PC Hardware reviews, overclocking, news - Master a networkb>: Layer II 1/5

The Data Link Layer deals with problems such as hardware addresses, networkb> topologies and how computers on a networkb> access the shared medium.
I've stated earlier that the Data Link Layer is where the networkb> topology is defined.
There are actually two aspects of a networkb>'s topology: the physical topology (the actual layout of the wires) and the logical topology (how data flows in a networkb>).

http://www.pchardware.ro/Articles/article.php?id=124 (521 words)



Networkb> Protocol Categories

There are exceptions to my categorizations that don't fit into the normal layering scheme, such as IGMP is normally part of the link layer, but I have tried to list these categorizations according to networkb> functions and their relative importance to the operation of the networkb>.
Critical - The networkb>, as designed, is useless without this ability.
Important - The networkb> could function, but would be difficult to use and manage.

http://www.comptechdoc.org/independent/networking/guide/netcategories.html (1009 words)



Paper 54

End host applications can add a byte string to the networkb> (IP) header as a new type of IP option, and that header is looked up and/or rewritten at intermediate hops, using a separate set of loadable tables.
DataRouter forwards networkb> layer packets using application layer tags, without requiring per-hop termination of transport protocols and the consequent reimplementation of transport services in the application.
In the Internet architecture, the networkb> layer forwards packets, the transport layer maintains ordering and reliability (if desired, as well as congestion control), and only the application deals directly with the payload data.

http://www.isi.edu/touch/pubs/iwan2003 (4369 words)



The Networkb> Book

Unlike traditional textbooks, it pursues a top-down approach to the topic, starting with the application layer and then describing the transport and networkb> layers, finally covering the physical layer.
The Networkb> Book aims to provide a comprehensive introduction to networking and distributed computing technologies.
You may not, however, retain copy in permanent storage, reproduce or distribute any of the Networkb> Book in part or in whole, using electronic or other media, without written permission of the author.

http://www.cs.columbia.edu/netbook (214 words)



IP

The Internetwork Protocol (IP) [RFC791] provides a best effort networkb> layer service for connecting computers to form a computer networkb>.
The most complex part of an IP router is concerned with determining the optimum link to use to reach each destination in a networkb>.
The IP protocol operates at the networkb> layer protocol of the OSI reference model and is a part of a suite of protocols known as TCP/IP.

http://www.erg.abdn.ac.uk/users/gorry/course/inet-pages/ip.html (389 words)



Networkb> layer firewall - Wikipedia, the free encyclopedia

In computer networks, a networkb> layer firewall works as a packet filter by deciding what packets will pass the firewall according to rules defined by the administrator.
Networkb> layer firewalls tend to operate very fast, and transparently to users.
Networkb> layer firewalls generally fall into two sub-categories, stateful and non-stateful.

http://en.wikipedia.org/wiki/Network_layer_firewall (215 words)



Networkb> Layer

All networkb> layer protocols use a header that includes both a source and destination address.
Networkb> layer addresses consist of two parts: A networkb> segment prefix which identifies the networkb> segment and a node suffix, which identifies the node on the segment.
The networkb> layer attempts to deliver packets from a node on one networkb> segment to another node that may be on another networkb> segment.

http://punch.engr.wisc.edu/~orchard/net-tutorial/network.html (321 words)



Cisco - OSI: The Networkb>-Layer

An ESH is sent by all ESs to a special data-link layer address that all ISs on that networkb> segment listen to.
Filter sets and filter expressions can be applied to inbound or outbound CLNP datagrams, IS-IS adjacencies (IS-IS routers that are on the same networkb> segment), ISO-IGRP adjacencies (ISO-IGRP routers that are on the same segment), ES-IS adjacencies (ESs and ISs that are on the same segment), and route redistribution.
The NSAP selector is used to distinguish between logical entities on the host (a transport entity in an ES or a networkb> entity in an IS).

http://www.cisco.com/warp/public/535/2.html (3846 words)



Networkb> layer firewall - definition of Networkb> layer firewall in Encyclopedia

Networkb> layer firewalls tend to operate very fast, and transparently to users.
Any normal computer running an operating system which supports packet filtering and routing can function as a networkb> layer firewall.
A networkb> layer firewall works as a packet filter by deciding what packets will pass the firewall according to rules defined by the administrator.

http://encyclopedia.laborlawtalk.com/Network_layer_firewall (216 words)



Firewall article - Firewall fire Firewalls construction Firewalls computer networking Networkb> - What-Means.com

Networkb> layer firewalls operate at a (relatively low) level of the TCP/IP protocol stack as IP-packet filters, not allowing packets to pass through the firewall unless they match the rules.
By extension, the computing world uses the term firewall for a piece of hardware or software which functions in a networked environment to prevent some communications forbidden by the networkb> policy.
Firewall article - Firewall fire Firewalls construction Firewalls computer networking Networkb> - What-Means.com

http://www.what-means.com/encyclopedia/Firewall (699 words)



Open Source - Internet & Web - OpenPlay

OpenPlay is a cross-platform networkb> abstraction layer designed to simplify the task of creating programs which communicate across multiple computers.
OpenPlay contains the functionality of the NetSprocket, providing comprehensive support including user interface elements for managing multiple players on a networkb>.
It completely abstracts both OpenTransport and Winsock, and its plug-in architecture makes it easy for you to support new transport protocols.

http://developer.apple.com/darwin/projects/openplay (157 words)



What is switch? - A Word Definition From the Webopedia Computer Dictionary

Users can also find extensive troubleshooting information, tips on getting applications to work through firewalls, product reviews on networkb> hardware and software, and more.
Switches operate at the data link layer (layer 2) and sometimes the networkb> layer (layer 3) of the OSI Reference Model and therefore support any packet protocol.
If networkb> connections, sharing computers, router problems or other networking issues are bogging you down, then the PracticallyNetworked.com discussion forum is the place to be.

http://www.webopedia.com/TERM/s/switch.html (482 words)



Webopedia: The 7 Layers of the OSI Model

The MAC sublayer controls how a computer on the networkb> gains access to the data and permission to transmit it.
This layer conveys the bit stream - electrical impulse, light or radio signal -- through the networkb> at the electrical and mechanical level.
This layer provides transparent transfer of data between end systems, or hosts, and is responsible for end-to-end error recovery and flow control.

http://www.webopedia.com/quick_ref/OSI_Layers.asp (426 words)



Firewalls FAQ

A simple router is the ``traditional'' networkb> layer firewall, since it is not able to make particularly sophisticated decisions about what a packet is actually talking to or where it actually came from.
Networkb> layer firewalls tend to be very fast and tend to be very transparent to users.
Application layer firewalls can be used as networkb> address translators, since traffic goes in one ``side'' and out the other, after having passed through an application that effectively masks the origin of the initiating connection.

http://www.faqs.org/faqs/firewalls-faq (14948 words)



Transmission Control Protocol article - Transmission Control Protocol transport layer IETF TCP/IP networkb> layer application layer - What-Means.com

This is why TCP exists: Applications send streams of 8-bit bytes to TCP for delivery onto the networkb> and TCP delineates the byte stream into appropriately sized segments, usually defined by a maximum transmission unit (MTU) size used by the data link layer below.
Acknowlegements for data sent, or lack of acknowlegements, are used by senders to implicity interpret networkb> conditions between the TCP sender and receiver.
Data Link Layers with a high probability of bit error rates may require additional link error correction/detection capabilities.

http://www.what-means.com/encyclopedia/Transmission_Control_Protocol (1434 words)



Networkb> Layers

If you monitor a networkb> and watch the pattern of packets emitted by a computer, you'll immediately understand the relationship between link-layer protocols and ``Sneezy''.
Programmers who design networkb> applications are incredibly grumpy -- they complain about the efficiency of other layers, the fundamental abstractions of the networkb>, the long hours, the difficulty of debugging, and the API they are forced to use.
Despite the success of the Internet in replacing all the previous attempts to build a global computer communication system, some engineers haven't updated their thinking from old descriptions of networks.

http://www.cs.purdue.edu/homes/dec/essay.network.layers.html (571 words)



RFC 1377 (rfc1377) - The PPP OSI Networkb> Layer Control Protocol (OSINLCP)

This document defines the NCP for establishing and configuring OSI Networkb> Layer Protocols.
NPDU Alignment OSI protocols have peculiar alignment problems due to the fact that they are often encapsulated in data link protocols with odd-length headers, while PPP defaults to even-length headers.
Networkb> Layer Protocol Identifier (NLPID) OSI Networkb> Layer protocols can be discriminated according to the first octet in each Networkb> Protocol Data Unit (NPDU, that is, packet), known as the Networkb> Layer Protocol Identifier (NLPID), which is defined in ISO/TR 9577 [7].

http://www.faqs.org/rfcs/rfc1377.html (2675 words)



Design issues for the networkb> layer

The transport layer (that is the host computer) should be shielded from the number, type and different topologies of the subnets he uses.
The networkb> layer has been designed with the following goals:
With this in mind, many applications perform their own error detection, flow and congestion control at a higher level in the protocol stack, that is, on their own machine, in the transport layer.

http://ntrg.cs.tcd.ie/undergrad/4ba2/network/design.html (812 words)



The evolution of application layer firewalls

For example, stateful firewalls don't detect worms that send strings of malicious code within legitimate protocols because stateful firewalls just look at networkb>-layer packet headers.
Remove spyware, adware, key-loggers and other malware, remote access to any computer on the networkb>, Remotely turn all your client machines on, computer trouble shooting - reporting, software mgmt, software deployment, chat system and more.
The issue with these application-layer firewalls seems to be whether they should be placed at all Internet gateways and evaluating whether they are worth the cost.

http://www.nwfusion.com/news/2004/0202specialfocus.html (1496 words)

About us | Why use us? | Press | Contact us

Copyright © 2006 CompWisdom.com Usage implies agreement with terms.

Topic: Network <b>layer<

Ads by Google